The document discusses malocclusion, defined as any deviation from normal tooth occlusion, highlighting its classification into various types for better understanding and treatment planning. It outlines individual tooth malpositions, relations of dental arches, and skeletal malocclusions, incorporating Edward Angle's classification system which categorizes malocclusions into Class I, II, and III. The drawbacks of Angle's classification and alternative incisor and canine relationships are also mentioned.